Question

I would like to use the Texture Memory for Interpolation of Data. I have 2 Arrays (namely A[i] and B[i]) and I would want to interpolate Data between them. I thought I could bind them to Texture Memory and set the interpolation but I am not sure how I can do that.

The examples that come with CUDA use the A[i-1] and A[i+1] for the interpolation.

Is there any way to do what I planned? I’m trying this because I think I can get a good speedup.

Answer 1

Yes, you can do this with texture memory, and it is fast. I personally use ArrayFire to accomplish these kinds of operations, because it is faster than I can hope to code by hand.

If you want to code by hand yourself in CUDA, something like this is what you want:

// outside kernel

texture<float,1>  A;
cudaChannelFormatDesc desc = cudaCreateChannelDesc<float>();
cudaArray *arr = NULL;
cudaError_t e = cudaMallocArray(&arr, &desc, 1, length);
A.filterMode = cudaFilterModePoint;
A.addressMode[0] = cudaAddressModeClamp;
cudaBindTextureToArray(A, arr, desc);

...

// inside kernel
    
valA = tex1D(A,1,idx)
valB = tex1D(B,1,idx)

float f = 0.5;
output  = (f)*valA + (1-f)*valB;

If you want to just plug-in ArrayFire (which in my experience is faster than what I try to code by hand, not to mention way simpler to use), then you’ll want:

// in arrayfire
array A = randu(10,1);
array B = randu(10,1);
float f = 0.5;
array C = (f)*A + (1-f)*B;

The above assumes you want to interpolate between corresponding indices of 2 different arrays or matrices. There are other interpolation functions available too.